Estimating biodiesel blend using virtual sensors and virtual sensing methods

Abstract

A method can include controlling, by at least one controller, an amount of hydrocarbons provided upstream of a diesel oxidation catalyst. The method can include determining, by the at least one controller, a first temperature of exhaust gas at an inlet of the diesel oxidation catalyst. The exhaust gas can be produced from combustion of fuel. The method can include determining, by the at least one controller, a second temperature of the exhaust gas at an outlet of the diesel oxidation catalyst. The method can include calculating, by the at least one controller, a lower heating value of the fuel based on the first temperature, the second temperature, the amount of hydrocarbons, and a flow rate of the exhaust gas. The method can include estimating, by the at least one controller, a percentage of biodiesel in the fuel based on the lower heating value.

What is claimed is: 
     
       1. A non-transitory computer-readable media having computer-readable instructions stored thereon that, when executed by at least one controller, cause the at least one controller to:
 control an amount of hydrocarbons provided upstream of a diesel oxidation catalyst (DOC); 
 determine a first temperature of exhaust gas at an inlet of the DOC, the exhaust gas produced from combustion of fuel; 
 determine a second temperature of the exhaust gas at an outlet of the DOC; 
 calculate a lower heating value (LHV) of the fuel based on the first temperature, the second temperature, the amount of hydrocarbons, and a flow rate of the exhaust gas; and 
 estimate a percentage of biodiesel in the fuel based on the LHV. 
 
     
     
       2. The non-transitory computer-readable media of  claim 1 , wherein the at least one controller is configured to output an indication of the estimated percentage of biodiesel in the fuel. 
     
     
       3. The non-transitory computer-readable media of  claim 1 , wherein the at least one controller is configured to determine that the first temperature is greater than or equal to a light-off temperature of the DOC prior to controlling the amount of hydrocarbons provided upstream the DOC. 
     
     
       4. The non-transitory computer-readable media of  claim 1 , wherein to calculate the LHV, the at least one controller is configured to determine a difference between the second temperature and the first temperature. 
     
     
       5. The non-transitory computer-readable media of  claim 1 , wherein the at least one controller is configured to compare the percentage of biodiesel in the fuel based on the LHV with a percentage of biodiesel in the fuel measured by a physical sensor. 
     
     
       6. The non-transitory computer-readable media of  claim 5 , wherein the at least one controller is configured to determine a tampering status of the physical sensor responsive to a determination that a difference between the percentage of biodiesel in the fuel based on the LHV and the percentage of biodiesel in the fuel measured by the physical sensor is greater than a threshold value. 
     
     
       7. The non-transitory computer-readable media of  claim 6 , wherein the at least one controller is configured to output an indication of the tampering status. 
     
     
       8. The non-transitory computer-readable media of  claim 5 , wherein the at least one controller is configured to estimate the percentage of biodiesel in the fuel based on at least one of a density of the fuel, a dynamic viscosity of the fuel, a dielectric constant of the fuel, or a resistivity of the fuel. 
     
     
       9. The non-transitory computer-readable media of  claim 5 , wherein the at least one controller is configured to estimate a percentage of hydrotreated vegetable oil in the fuel based on the LHV. 
     
     
       10. The non-transitory computer-readable media of  claim 1 , wherein:
 the at least one controller is configured to control a first injection of hydrocarbons prior to calculating the LHV; and 
 the at least one controller is configured to control a second injection of hydrocarbons based on the calculated LHV. 
 
     
     
       11. The non-transitory computer-readable media of  claim 1 , wherein the at least one controller is configured to control the first temperature, the amount of hydrocarbons that are injected, and the flow rate of the exhaust gas to achieve the second temperature of less than 450° C. 
     
     
       12. The non-transitory computer-readable media of  claim 1 , wherein:
 the at least one controller is configured to initiate an injection event comprising injection of hydrocarbons upstream of the DOC; and 
 the injection event occurs over a period of time of less than a threshold time. 
 
     
     
       13. The non-transitory computer-readable media of  claim 12 , wherein the threshold time is five minutes. 
     
     
       14. The non-transitory computer-readable media of  claim 1 , wherein the flow rate of the exhaust gas is determined based on one or more engine operating conditions. 
     
     
       15. An aftertreatment system comprising the at least one controller and the DOC of  claim 1 . 
     
     
       16. The aftertreatment system of  claim 15 , further comprising a hydrocarbon insertion assembly coupled with the at least one controller, the at least one controller configured to control injection of hydrocarbons upstream of the DOC. 
     
     
       17. A method comprising:
 controlling, by at least one controller, an amount of hydrocarbons provided upstream of a diesel oxidation catalyst (DOC); 
 determining, by the at least one controller, a first temperature of exhaust gas at an inlet of the DOC, the exhaust gas produced from combustion of fuel; 
 determining, by the at least one controller, a second temperature of the exhaust gas at an outlet of the DOC; 
 calculating, by the at least one controller, a lower heating value (LHV) of the fuel based on the first temperature, the second temperature, the amount of hydrocarbons, and a flow rate of the exhaust gas; and 
 estimating, by the at least one controller, a percentage of biodiesel in the fuel based on the LHV. 
 
     
     
       18. The method of  claim 17 , further comprising:
 outputting, by the at least one controller, an indication of the estimated percentage of biodiesel in the fuel. 
 
     
     
       19. The method of  claim 17 , further comprising:
 initiating, by the at least one controller, an injection event comprising injection of hydrocarbons upstream of the DOC; 
 wherein the injection event occurs over a period of time of less than five minutes. 
 
     
     
       20. The method of  claim 17 , further comprising:
 estimating, by the at least one controller, the percentage of biodiesel in the fuel based on at least one of a density of the fuel, a dynamic viscosity of the fuel, a dielectric constant of the fuel, or a resistivity of the fuel.